How to make a cast iron shader that has scrapes?
The easiest way to do it is to use the Box option of the Image Texture node:

Find a scratch texture image:



Create this node chain: Texture Coordinate &gt; Mapping &gt; Image Texture &gt; ColorRamp &gt; plugged into the Roughness socket of the Principled BSDF. In the Image Texture, switch from Flat to Box so that the image is projected on all the axis. If needed, increase the Blend so that no seam is visible. Play with the ColorRamp to increase or decrease the Roughness. Choose the Principled Base Color:



Here is the kind of effect you can get: